Machine-inserted service t with conical web



May 13, 1958 E. H. MUELLER ET AL 2,834,614

MACHINEEINSERTED SERVICE T WITH CONICAL WEB Filed June 26, 1953 FIG]. F162.

24 Prior AM 24 A l, A

IN VEN TOR 1 32122175. Mia/ er 1/0/12? If 5m it ATTORNEY United States Patent MACHINEJNSERTED SERVICE T WITH CONICAL WEB Frank H. Mueller and John J. Smith, Decatur, 111., as-

sig nors to Mueller Co., Decatur, 11]., a corporation of Application June 26, 1953, Serial No. 364,370 2 Claims. or. 285-119) This invention relates to a service T adapted to be screwed to a tapped aperture in a main for connecting a branch or service pipe to the latter without loss of pressure, i. e., escape of fluid from the main to the atmosphere during the connecting operation. More especially, this invention pertains to an improved service T of the type disclosed in the copending application of John J. Smith, Serial No. 283,881, filed April 23, 1952, now Patent No. 2,756,486.

The service T disclosed in the aforementioned copending application has a through bore and a lateral outlet. One end of the T, i. e., the inlet end, is provided with exterior threads for engagement in a tapped aperture in a main, while the other end of the T is provided with exterior threads for the connection thereto of an enclosed drilling and plugging machine having a pressure chamber through which tools may be manipulated. The machine-connectable end of the T also is interiorly threaded for the reception of a closure plug. For reasons later described, the bore of the T is-blocked by an integral web located at a position between the inlet end of the T and its lateral outlet.

In connecting a T of this type to a main, the main first is drilled and tapped without loss of pressure by an enclosed machine, as is well known in the art. By use of the same drilling and tapping machine, the service T is then inserted and screwed into the tapped aperture in the main without loss of pressure. Thereafter the drilling and T-inserting machine is removed from the main,' whereupon the service pipe may be connected to the T and completely. installed and tested without escape of fluidfrom the. main because of the blocking web in the T. After the service pipe has been installed, an enclosed drilling and plugging machine of known construction is connected to the T and the bore-blocking web is drilled out to allow fluid to flow from the main through the T and into the service pipe. The drilling and plugging machine is then utilized to plug andcap the T in a conventional manner, again without loss of pressure.

Ts of the type under consideration also are provided with a bore section of uniform diameter located inwardly of the plug-engaging interior threads, such bore section being adapted to receive an expansible pipe stopper to shut ofl flow from the main to. the service pipe, after the web has been drilled out, in order to enable repairs to be made to the service pipe, or for other reasons.

A service T ofthe type under consideration usually is made'by a casting operation, after which its bore and lateral outlet are formed by drilling operations. Subsequent to the drilling operations, the interior and exterior T threads are formed by an appropriate threading machine. The inner surface of the integral web blocking the. through bore of the T is provided with a conical depression which serves to center a drill when the web is being drilled out as aforedescribed. The depression is formed by the conical end of a metal drill in the boreforming operation. The outer surface of the web, which ordinarily is flush with the inlet end of the T, is flat.

; machine (not shown).

The result of the aforementioned type of T construction is to leave an integral bore-blocking web which has a drill-centering conical depression in its interior surface and while its exterior surface is flat orplane and disposed transversely of the bore of the T. Since the outer or exterior surface of the web is flat, during the subsequent web-drilling operation the drill must cut away a considerable amount of metal and also must travel, while under load, a distance'equal to the thickness of the web, measured axially of the bore, at a radial location corresponding to the peripheral outline of the drill. In other words, the drill must travel, while cutting, a distance considerably greater than the minimum thickness of the web.

Drilling machines, which are used to drill out the boreblockingweb of a service T after the latter has been installed in a main, are advanced into the work either by a feed screw, in the event thatthe drilling machine is power driven, or by a hand-operated feed screw or nut in the event that the drilling machine is manually operated. In either event, however, when the drill has to travel a considerable distance and also cut away a large quantity of metal before completely penetrating through the web, the time consumed for the drilling operation, though relatively small, becomes excessive. It can readily be seen that when a large number of service Ts have to' be installed by a public utility, the summation of excessive drilling times greatly adds to the labor costs involved.

Accordingly, it is an object of this invention to provide a service T of the type under consideration with a bore-blocking web configuration which greatly shortens the time necessary to drill therethrough after the T has been installed in a main.

It is another object of this invention to provide'a service T of the type under consideration with a blocking web which is sufiiciently strong to Withstand main pressures, yet which requires less axial travel and less metal-cutting for a drill in the drilling-out operation than service Ts heretofore known.

Other objects and advantages of the invention will be apparent from the following description and accompanying drawings, in which:

. Figure l is a longitudinal sectional view of a service T of the "type on which this invention is an improvement.

Figure 2 is a longitudinal sectional view of a service T embodying this invention.

Figure 3 is an enlarged fragmentary longitudinal sec-- tional view of a portion of the service T illustrated'in Figure 2, and showing a drill in position therein at thestart of the drilling operation.

Figure 4 is an elevational view, partly in vertical section,

illustrating a service T embodying this invention installed in a main and with a drill in the position assumed subsequent to complete penetration through the bore-blocking web.

Figure 5 is a view corresponding to Figure 3 *but 14 that is surrounded by an exterior boss 16 and which may have interior threads 18 for the connection of a service pipe (not shown) thereto. The inlet end 20 of the T is provided with exterior threads 22, preferablyiron pipe threads, for connecting'the T 10 into a previously tapped opening in a main (not shown). of the T 10 is provided with interior threads 24 for the reception of a threaded plug (not shown) and exterior. threads 26 for the connection of a drilling and plugging The bore 12 of the T10 consists,

of a cylindrical section 28 of substantially the same diam- The other end eter as the minimum diameter of the interior threads 24 and extending therefrom just past the lateral outlet 14, at which point the bore is restricted to provide an interior shoulder 39 and extends as a section 32 of reduced diameter to the inlet end 20 of the T.

At the inlet end 20 of the T the reduced bore section 32 is blocked by an integral web 34 having a conical depression 36 in its interior face. The conical depression 36 is formed by the conical end of the metal drill (not shown) which formed the reduced bore section 32. The depression 36 serves a purpose later described. The end surface 38 of the inlet end 20 of the T, which also constitutes the exterior surface of the web 34, is fiat and extends transversely of the axis of the bore 12.

When the T 10 has been installed in a main (not shown), as heretofore described, and as set forth in considerable detail in the aforementioned copending application to John J. Smith, the web 34 is drilled out by a metal drill 40 to allow flow to take place from the main through the T It) and into a service pipe connected to the lateral outlet 14- of the T. It will be seen, however, that the distance which the drill 4t must travel in order to pass completely through the web 34 is equal to the thickness of the web at the peripheral outline of the drill 40, such distance being generally indicated at d. Obviously this distance d must be travelled in order for the drill 40 to pass completely through the web 34, even though the drill first penetrates the web at the center of the conical depression 36.

Referring now to Figure 2 of the drawings, the service T 44 embodying this invention and illustrated therein is substantially identical to the service T shown in Figure 1, except for the configuration and construction of the end surface 46 of the inlet end 29 and consequently the exterior side of the bore-blocking web 48. Hence, the parts of the T 44 which are the same as the corresponding parts of the T It) are identified by the same reference characters. The inlet end 20 of the T 44 is provided with an exterior bevel, preferably large enough so that the entire end surface 46 of the T has a convexly conical configuration, as shown. This end surface configuration may be imparted to the T 44 illustrated in Figure 2 by a simple machining operation on a T of the type shown in Figure 1. Preferably, the angle of the bevel imparted to the T 44 shown in Figure 2 is the same as the angle of the conical depression 36 in the interior surface of the bore-blocking web 48, so that the interior and exterior surfaces of the web are substantially parallel. In other words, the thickness of the web 48, axially of the bore 12, is substantially uniform throughout the entire extent of the web.

Referring now to Figure 3 of the drawings, it will be seen that the conical depression 36 in the interior surface of the web 48 is complementary to the conical end of a metal drill 40 which is to be used to drill out the web in the manner aforedescribed. Hence, this conical depression 36 serves to center the drill 40 for the drilling operation. It will be seen that the distance that the drill 40 must travel in order to effect complete penetration of the web 48 and drill a hole 52 therein equal to the diameter of the drill, as shown in Figure 4, is equal only to the thickness of the web measured axially of the bore 12, as indicated at d. In other words, this distance d is substantially less than the distance d which would have been necessary for the drill 40 to travel under load were it not for the exterior bevel on the end of the T 44.

It will be seen that the thickness of the web 48 is substantially the same as the minimum thickness of the web 34 of prior art Ts, i. e., the thickness at the center of the interior depression 36. Hence, the web 48 is substantially as strong as prior art TS and has ample strength to resist the pressure in a main 54 when installed therein, as shown in Figure 4. It further will be seen that the bevelling operation removes a considerable amount of metal which, lacking its removal, it otherwise would be necessary to drill out. Hence, the metal removal alone reduces the drilling time.

Although the bevelled end surface 46 has been shown as conical for maximum benefits, it will be seen that a bevel which provides only a frusto-conical end surface (not shown) will provide some degree of beneficial results.

Referring now to Figure 5, there is shown therein a modified T 56 embodying this invention. In this modification, a T of the type shown in Figure 1 is machined to form an annular recess 58 in the end surface of its inlet end 20. Viewed in radial section, the inner and outer walls 60 and 62 of the annular recess are substantially outwardly divergent. The inner wall 60 defines a convexly conical surface that has the same angle as and extends substantially parallel to the interior concavely conical surface 36 of the bore-blocking web 64. The bottom of the annular groove or recess 58 preferably is of substantially the same diameter as the diameter of the smaller bore section 32 of the T 56. As shown, preferably the outer wall 62 of the annular recess 58 is inclined outwardly so that the major diameter of the annular recess is somewhat greater than the diameter of the smaller bore section 32 of the T.

It will be seen that the T construction shown in Figure 5 provides the same drilling-time-saving results as the T construction shown in Figures 2 and 3, in that a drill need travel only a relatively short distance and cut out a minimum amount of metal in order to effect complete penetration of the bore-blocking web 64.

It will thus be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that changes may be made in the specific embodiments shown and described to illustrate the principles of this invention without departing from such principles. Accordingly, this invention includes all modifications encompassed within the spirit and scope of the following claims.

We claim:

1. A service T having a through bore and a lateral outlet, one end of said T being exteriorly threaded for engagement in a tapped opening in a main and the other end of said T being interiorly threaded for reception of a threaded plug and provided with exterior means for the attachment of means defining a pressure chamber through which tools may be manipulated, and a relatively thin conical drillable web of uniform thickness throughout blocking that section of said through bore extending between said one T end and said lateral outlet with the concave surface of said web facing said other T end, whereby in drilling through said web from said concave surface thereof with a metal drill having a conical tip complementary to said concave surface, the drill need travel a distance equal only to the thickness of said web measured axially of said bore.

2. In a service T having a through bore and a lateral outlet, exterior threads at one end thereof for engagement in a tapped opening in a main, interior threads at the other end thereof for reception of a threaded plug and exterior means at the said other end for attachment of means defining a pressure chamber through which tools may be manipulated, the combination of a relatively thin, integral drillable web of uniform thickness throughout and having a concavely conical interior surface blocking the said bore at the said one end of the T, and an exterior bevel on the said one T end defining at least a portion of the exterior surface of the said web, whereby in drilling through said web from said interior surface thereof with a metal drill having a conical tip complementary to said interior surface, the drill need drill a distance equal only to the thickness of said web measured axially of said bore.

(References on following page) UNITED STATES PATENTS Bernardi Sept. 18, 1900 Mueller et al. Feb. 12, 1929 McAndrew May 31, 1932 Markle Oct.,31, 1933 Lovekin May 29, 1934 Mueller Apr. 2, 1935 6 Gornell July 11, 1939 Crampton Jan. 26, 1943 Mueller Sept. 20, 1949 Ragan Apr. 4, 1950 Mueller June 9, 1953 FOREIGN PATENTS France 1910 

